diff --git a/sheet.go b/sheet.go
index b615ae5..2344218 100644
--- a/sheet.go
+++ b/sheet.go
@@ -24,9 +24,9 @@ import (
 	"github.com/mohae/deepcopy"
 )
 
-// NewSheet provides a function to create a new sheet by given worksheet name,
-// when creating a new XLSX file, the default sheet will be create, when you
-// create a new file.
+// NewSheet provides function to create a new sheet by given worksheet name.
+// When creating a new XLSX file, the default sheet will be created. Returns
+// the number of sheets in the workbook (file) after appending the new sheet.
 func (f *File) NewSheet(name string) int {
 	// Check if the worksheet already exists
 	if f.GetSheetIndex(name) != 0 {
@@ -221,9 +221,9 @@ func replaceRelationshipsNameSpaceBytes(workbookMarshal []byte) []byte {
 	return bytes.Replace(workbookMarshal, oldXmlns, newXmlns, -1)
 }
 
-// SetActiveSheet provides a function to set default active worksheet of XLSX by
-// given index. Note that active index is different with the index that got by
-// function GetSheetMap, and it should be greater than 0 and less than total
+// SetActiveSheet provides function to set default active worksheet of XLSX by
+// given index. Note that active index is different from the index returned by
+// function GetSheetMap(). It should be greater than 0 and less than total
 // worksheet numbers.
 func (f *File) SetActiveSheet(index int) {
 	if index < 1 {
@@ -257,8 +257,8 @@ func (f *File) SetActiveSheet(index int) {
 	}
 }
 
-// GetActiveSheetIndex provides a function to get active sheet of XLSX. If not
-// found the active sheet will be return integer 0.
+// GetActiveSheetIndex provides a function to get active sheet index of the
+// XLSX. If not found the active sheet will be return integer 0.
 func (f *File) GetActiveSheetIndex() int {
 	buffer := bytes.Buffer{}
 	content := f.workbookReader()